1. Field of the Invention
The present invention relates to objects or articles such as machine parts, structure component members, pipes for water supply and others, various sheets, toys or their parts, sporting goods or their parts, rain goods or their parts, and diaphragms for diaphragm pumps, e.g., for artificial hearts, and particularly relates to an object having a portion, which is to be in contact with another object (e.g., another article, part, fluid or ground) and is entirely or partially made of at least one kind of material selected from a group including polymer material such as resin or rubber as well as glass.
2. Description of the Related Art
Polymer material such as organic polymer material (e.g., resin and rubber) are now utilized in various fields. For example, such material is used for partially or entirely forming objects such as machine parts, structure component members, pipes, sheets, toys or their parts, sporting goods (or articles) or their parts, rain goods (or articles) or their parts, or diaphragms for diaphragm pumps, e.g., for artificial hearts. The glass is also used for window panes of automobiles and others.
The object having a portion which is to be in contact with another object and is partially or entirely made of polymer material is generally required or desired to have such a feature that the portion to be in contact with another object and made of polymer material has an improved sliding property with respect to another object and/or can suppress wear and deterioration due to friction. For these purposes, lubricant oil or grease is applied to the portion, or the portion is impregnated with lubricant oil. Also, the portion may be made of material containing oil added thereto.
Also, the portion made of polymer material may be coated with a film made of fluorine-contained resin (e.g., polytetrafluorethylene) having a good lubricity.
If transmission of oxygen, water vapor or another gas is to be suppressed at the portion made of polymer material, a gas barrier resin film may be formed at the surface of the portion, for example, by applying resin thereto.
If a water repellency is required at the portion made of polymer material, a water-repellent resin film may be formed at the surface of the portion by applying resin thereto.
The above processing may not be employed in some cases.
However, a problem arise in the method in which lubricating oil or grease is used for improving sliding property and/or suppressing wear and deterioration due to friction, and particularly oil or grease is applied to the surface of the portion made of polymer material. More specifically, in this method, relatively good characteristics are achieved at the start of use. However, oil or grease on the surface is dispersed, absorbed or removed with time, so that the sliding property is impaired, and wear and deterioration of the surface are liable to occur. According to the method in which the portion made of polymer material is impregnated with oil or is made of material containing oil, relatively good characteristics can be achieved at the start of use. However, the oil contained at the surface portion is absorbed into another object (i.e., contact object) with time. By this or other reasons, the amount of oil spreading over the surface decreases, so that the sliding property lowers, and wear and deterioration of the surface are liable to occur.
Even if oil or grease is present on the surface of the portion made of polymer material, wear and deterioration due to friction with the contact object cannot be sufficiently suppressed if the contact object in contact with the above portion is made of, e.g., metal and therefore is hard.
According to the method in which a fluorine-contained resin film is formed at the surface of the portion made of polymer material, wear and deterioration of the surface are liable to occur due to friction with another object made of hard material such as metal.
According to the method in which a resin film having a gas barrier property is formed at the portion made of polymer material, a good sliding property with respect to another object cannot be maintained for a long term, because the film surface is made of resin. Further, wear and deterioration of the surface are liable to occur due to friction with another object made of hard material, such as metal.
Similar problems arise in the method in which the portion made of polymer material is coated with a water-repellant resin film.
If any one of the above methods is not employed, problems relating to wear resistance arise from the start of use.
The foregoing will now be discussed more in detail. Various kinds of machine parts such as gears and rollers, structure component members such as walls and floors, toys and their parts such as gears and sliding parts, and various kinds of pipes and sheets may have such structures that each object is partially or entirely made of polymer material such as resin or rubber. The object and particularly a portion thereof made of polymer material for contact with another object may be processed or formed as follows for improving a sliding property with respect to another object (contact object) and preventing wear and deterioration due to contact with the contact object. According to the above processing or formation, oil or grease may be applied to the surface, or the object may be impregnated with oil. Also, the portion may be made of material containing oil added thereto.
For a pipe requiring a gas barrier property, the outer surface of the pipe may be coated with a resin film having a gas barrier property for suppressing transmission of oxygen, water vapor and other gases.
A sheet may be made of material impregnated with oil or containing oil added thereto for improving a sliding property with respect to a contact surface of a sheet support member, object, ground, floor or the like supporting or covered with the sheet, and thereby preventing wear and deterioration due to contact. This method is also employed for preventing smearing of the sheet by water droplets, rain, mud and others.
If oil or grease is employed, the amount of oil or grease at the surface of the portion made of polymer material decreases with use and therefore the sliding property is impaired as already described, so that wear and deterioration of the surface are liable to occur. Even in the case where oil is present at the portion made of polymer material, wear and deterioration due to friction with a contact object cannot be sufficiently suppressed if the contact object in contact with the portion is made of hard material such as metal.
Likewise, a pipe coated with a resin film having a gas barrier property cannot maintain a good sliding property with respect to a contact object for a long term, because the surface is made of resin. Also, wear and deterioration are liable to occur at the surface due to friction with the contact object made of hard material such as metal.
In a sheet impregnated with oil or made of material containing oil added thereto, wear and deterioration are liable to occur at the surface thereof due to contact with a support member of the sheet, a contact object laid on the sheet, a contact object to be covered by the sheet, the ground or the like. This results in lowering of the sliding property and water repellency. As a result of lowering of the water repellency, water droplets, raindrops, mud and others are liable to adhere thereto.
For automobile parts, a polymer material such as rubber or resin, is widely used as a material for vibration dampers, hoses, tires and sealing members.
Vibration dampers and hoses for automobiles, which have surfaces made of polymer material, are required or desired to have an improved sliding property with respect to other objects (i.e., contact objects). Also, it is also required or desired to prevent wear due to contact with contact objects as well as deterioration. For these purposes, grease is applied to the surface, or the damper is made of material containing oil added thereto.
Hoses for automobiles may be coated with resin films having a gas barrier property for suppressing transmission of oxygen, water vapor or other gases. Automobile tires are required to suppress wear and deterioration due to contact with wheels, and are also required to suppress deterioration due to external light and exhaust gas. For these purposes, grease or wax may be applied to the surface, or the tire may be made of material containing oil added thereto.
Automobile sealing members are desired to prevent wear and deterioration due to contact with contact objects in contact with the seal members. For this purpose, grease may be applied to the surface, or oil may be added to the material thereof.
According to the method in which grease or wax is applied to the surfaces of the vibration dampers, hoses, tires and seal members for automobiles, desired characteristics such as a good sliding property with respect to the contact object may be obtained at the start of use. However, the grease or wax on the surface may be dispersed, absorbed to other objects or removed with time, which results in wear and deterioration of the surface as well as lowering of a sliding property.
According to the method in which the vibration dampers, hoses, tires and seal members for automobiles are made of material containing oil added thereto, desired characteristics such as a good sliding property may be obtained at the start of use. However, the oil contained in the surface portion decreases in amount due to absorption into other objects with time, which results in wear and deterioration of the surfaces as well as lowering of a sliding property.
Automobile vibration dampers are usually arranged to be in contact with objects made of metal. Automobile hoses are often fixed by metal fasteners. Automobile tires are usually in contact with wheels made of metal. Automobile seal members are usually in contact with pipes or the like made of metal. In these cases, the method of employing grease applied to the surface and the method of adding oil to the material cannot sufficiently prevent wear and deterioration of the surface.
The automobile hoses coated with resin films having a gas barrier property cannot maintain a good sliding property with respect to other objects for a long term, because their surfaces are made of resin. Also, wear and deterioration are liable to occur due to friction with contact objects made of hard material such as metal.
Automobile tires may also suffer from another problem. More specifically, external water vapor is liable to move into the tire. If the tire includes an inner tube, the water vapor is liable to deteriorate the tube. In rain, water and mud are liable to remain in tire grooves at the outer surface.
Automobile diaphragms are specifically used in a diaphragm pump for window washer fluid, a diaphragm pump used in a fuel supply system and a diaphragm valve, and are generally made of polymer material such as rubber or resin. For automobile valve parts, it has been proposed to use resin having a relatively good heat resistance such as polyimide resin or a polytetrafluorethylene resin. Automobile window panes are brought into contact with wiper blades for wiping raindrops. Automobile bodies are usually coated with decorative paint films made of resin. However, these parts are not particularly treated to have good wear resistance and others.
However, the automobile diaphragm made of polymer material suffers from problems that wear and deterioration are liable to occur due to contact with a part or the like which is made of metal and is employed for fixing the diaphragm, and that fluid such as liquid handled by the diaphragms is liable to adhere to the diaphragm.
Automobile valve parts made of resin may suffer from wear, deterioration and lowering of a sliding property due to contact between valves and valve seats.
Automobile window panes may suffer from such problems that a wiper blade cannot sufficiently remove raindrops on the pane, and that raindrops start to remain on the pane immediately after wiping and therefore cannot be removed sufficiently. Further, the panes may be scratched by sand dust in a wind.
Automobile bodies may suffer from such problems that decorative paint films are liable to be peeled off due to contact with other objects, and that a water repellency is impaired and therefore dust adhered to the paint film cannot be removed easily.
For parts of image forming apparatuses, polymer material such as resin or rubber is widely used. For example, thermoplastic resin is widely used for various kinds of frames, record member trays, gears, bearings and others. Thermosetting resin is used for gears, bearings and others. Rubber is used in surface portions of various rollers such as a developing roller in a developing device, fixing and pressure rollers in a fixing device for fixing a toner image on the record member under heat and pressure, an application roller for applying a release agent to the fixing roller, a transfer roller for transferring a toner image produced by developing a latent image on an electrostatic latent image carrier onto a paper sheet, and a cleaning roller for removing toner remaining on the electrostatic latent image carrier. Also, rubber is used as a surface material of rotary parts, such as a transfer belt which may be employed as transfer means, and other belts.
These image forming apparatus parts which have surfaces made of polymer material do not have a sufficient sliding property with respect to contact objects. Therefore, in order to improve a sliding property of resin parts such as gears and bearings, which require a sufficient sliding property as described before, grease may be applied to the surfaces, or they may be made of material containing oil added thereto. For parts such as a roller and a belt, of which surface portions are primarily made of rubber, surfaces thereof may be coated with films of fluorine-containing resin (e.g., polytetrafluorethylene) having a good sliding property, or they may be made of rubber containing oil added thereto.
However, according to the method in which grease is applied to the surface of the sliding part such as a gear or a bearing, the amount of grease on the surface gradually decreases with use, and therefore the sliding property lowers as already described. According to the method in which the forming apparatus part is made of material containing oil added thereto, the amount of oil at the surface gradually decreases with use, and therefore the sliding property lowers as already described. In the latter case, the fixing device parts or the like may suffer from such a problem that only limited kinds of oil can be used because the fixing devices are usually heated to about 200° C. for fixing the toner image on the sheet.
According to the method in which parts are coated with fluorine-containing resin films, base members of the image forming apparatus parts can be made of only limited kinds of material, because baking or sticking of the films must be performed at a temperature from 360 to 400° C. for 20 to 40 minutes.
Sporting goods or articles, bicycle parts or the like are made of polymer material such as rubber or resin in many cases. More specifically, rubber is used, for example, in sealing members of mountaineering and camping tents, balls, sport shoes and bicycle tires, and particularly is used as their major material or surface material. Resin is used in frames and guts of tennis and badminton rackets, golf clubs, sport shoes, disks used as a substitute for spokes of bicycle wheels, rims of bicycle wheels or the like, and particularly is used as their major material or surface material.
Among these objects, the objects having surfaces made of rubber may be required to have a good sliding property with other objects for preventing wear and deterioration due to contact with other objects or to have an improved water repellency. For these purposes, grease or wax may be applied to the surface, or oil may be added into the material of the object. These measures are not employed in objects having surfaces made of resin.
Polymer material such as rubber or resin is usually used in rain shoes, umbrellas, raincoats or other rain articles.
Diaphragms employed in diaphragm pumps for artificial hearts or the like are made of polymer material such as silicon rubber.
However, according to the above method for the sports goods and bicycle parts, and particularly the method in which grease or wax is applied to the surfaces of the foregoing sealing members, balls, bicycle tires or the like, the amount of grease or wax on the surface gradually decreases with use, and therefore the sliding property lowers as already described, so that wear and deterioration of the surface are liable to occur. Also, the water repellency is liable to lower, and therefore adhesion of smear is liable to occur. According to the method in which the object is made of material containing oil added thereto, the amount of oil at the surface gradually decreases with use, and therefore similar problems arise as already described.
Friction occurs, for example, between a seal member, which provides sealing between a tent sheet and a pole, and the metal pole. Also, friction occurs between a ball and the ground, bat, racket or the like. Friction further occurs between a bicycle tire and a metal rim when air is supplied or discharged from the tire. The friction thus occurred tends to wear or deteriorate the surface, which impairs a sliding property and/or a water repellency. Lowering of the water repellency results in a problem that a carry of a golf ball or the like decreases.
Similar problems arise in sport goods and their parts having surfaces made of resin. More specifically, wear and deterioration of the surface thereof are liable to occur, and therefore a sliding property and water repellency are impaired due to contact of the rackets and golf clubs with other objects, mutual contact between guts made of resin, and contact between rims and tires.
A low water repellency of the bicycle disks cannot sufficiently suppress adhesion of raindrops in the rain, which may prevent high-speed cycling.
Rain goods made of rubber or resin are liable to be damaged by contact with other objects. Also, raindrops and mud adhered onto the rain articles cannot be easily removed due to an insufficient water repellency.
The diaphragm made of polymer material suffers from such problems that wear and deterioration are liable to occur due to contact with a fastener or the like, and fluid such as liquid or the like handled by the diaphragm is liable to adhere and remain on the diaphragm.